<html>
    <body>
        <table border="1">
            <tr>
                <th>One</th>
                <th>Two</th>
                <th colspan="2">Three</th>
                <th>Five</th>
            </tr>
            <tr>
                <td>cat</td>
                <td><a onclick="alert('alert cat two')">foo</a></td>
                <td><a onclick="alert('alert cat three')">foo</a></td>
                <td><a onclick="alert('alert cat four')">foo</a></td>
                <td><a onclick="alert('alert cat five')">foo</a></td>
            </tr>
            <tr>
                <td>dog</td>
                <td colspan="2"><a onclick="alert('alert dog two')">foo</a></td>
                <td><a onclick="alert('alert cat four')">foo</a></td>
                <td><a onclick="alert('alert cat five')">foo</a></td>
            </tr>
            <tr>
                <td>bird</td>
                <td><a onclick="alert('alert bird two')">foo</a></td>
                <td colspan="2"><a onclick="alert('alert bird three')">foo</a></td>
                <td><a onclick="alert('alert cat five')">foo</a></td>
            </tr>
            <tr>
                <td>cow</td>
                <td><a onclick="alert('alert cat two')">foo</a></td>
                <td><a onclick="alert('alert cat three')">foo</a></td>
                <td colspan="2"><a onclick="alert('alert cat four')">foo</a></td>
            </tr>  
        </table>
    </body>
</html>